<!-- 多图上传组件 -->
<template>
  <el-upload v-model:file-list="fileList" list-type="picture-card" :before-upload="handleBeforeUpload" :http-request="handleUpload" :on-remove="handleRemove" :on-preview="previewImg" :limit="props.limit">
    <i-ep-plus />
  </el-upload>

  <el-dialog v-model="dialogVisible">
    <img referrerPolicy="no-referrer" w-full :src="previewImgUrl" alt="Preview Image" />
  </el-dialog>
</template>

<script setup lang="ts">
import { UploadRawFile, UploadRequestOptions, UploadUserFile, UploadFile, UploadProps } from 'element-plus'
import { uploadFile, deleteFile } from '@/api/file'

const emit = defineEmits(['update:modelValue'])

const props = defineProps({
  /**
   * 文件路径集合
   */
  modelValue: {
    type: Array<string>,
    default: [] as Array<string>
  },
  /**
   * 文件上传数量限制
   */
  limit: {
    type: Number,
    default: 10
  }
})

const previewImgUrl = ref('')
const dialogVisible = ref(false)

const fileList = ref([] as UploadUserFile[])
watch(
  () => props.modelValue,
  (newVal: string[]) => {
    const filePaths = fileList.value.map((file) => file.url)
    // 监听modelValue文件集合值未变化时，跳过赋值
    if (filePaths.length > 0 && filePaths.length === newVal.length && filePaths.every((x) => newVal.some((y) => y === x)) && newVal.every((y) => filePaths.some((x) => x === y))) {
      return
    }

    fileList.value = newVal.map((filePath) => {
      return { url: filePath } as UploadUserFile
    })
  },
  { immediate: true }
)

/**
 * 自定义图片上传
 *
 * @param params
 */
async function handleUpload(options: UploadRequestOptions): Promise<any> {
  // 上传API调用
  const { data: fileInfo } = await uploadFile(options.file)

  // 上传成功需手动替换文件路径为远程URL，否则图片地址为预览地址 blob:http://
  const fileIndex = fileList.value.findIndex((file) => file.uid == (options.file as any).uid)

  fileList.value.splice(fileIndex, 1, {
    name: fileInfo.name,
    url: fileInfo.url
  } as UploadUserFile)

  emit(
    'update:modelValue',
    fileList.value.map((file) => file.url)
  )
}

/**
 * 删除图片
 */
function handleRemove(removeFile: UploadFile) {
  const filePath = removeFile.url

  if (filePath) {
    deleteFile(filePath).then(() => {
      // 删除成功回调
      emit(
        'update:modelValue',
        fileList.value.map((file) => file.url)
      )
    })
  }
}

/**
 * 限制用户上传文件的格式和大小
 */
function handleBeforeUpload(file: UploadRawFile) {
  if (file.size > 2 * 1048 * 1048) {
    ElMessage.warning('上传图片不能大于2M')
    return false
  }
  return true
}

/**
 * 预览图片
 */
const previewImg: UploadProps['onPreview'] = (uploadFile) => {
  previewImgUrl.value = uploadFile.url!
  dialogVisible.value = true
}
</script>
